The present invention relates to a former for folding one or a plurality of paper webs which are placed on top of each other. The former has at least one lateral guide element in addition to a former plate.
A device for the automatic feeding of a start of a paper web is known from DE 196 12 924 A1, wherein the paper web is guided over turning bars or is fed to a former by means of endless driven conveyor belts.
DE-AS 11 41 650 describes a former with conveying rollers for webs of material.
JP 06-247622 A discloses a former with rotating guide elements for reduction of the friction between the former and the web.
GB 862 296 A and EP 0 415 077 A1 each disclose a former with driven conveying means located in the interior. These conveying means convey sheets or webs in the conveying plane of the not yet folded sheets or webs.
The object of the present invention is based on providing a former. This object is attained by providing a former for longitudinally folding one or several webs which are placed on top of each other. The former has one or two lateral guide elements in addition to the former plate.
The advantages which can be achieved by means of the present invention lie, in particular, in that in the course of the draw-in process of a paper web into the web-fed rotary printing press, the paper webs of a paper web train are automatically fed to the folding unit. Introduction or re-introduction of individual paper webs can take place at the speed of the press. In the course of this, the paper webs are each guided with prestress between conveyor belts or conveying devices. These conveying devices act on both sides of the outer paper web, so that the interiorly located paper webs are carried along, clamped by the conveyor belts or conveying devices. A displacement of the paper webs themselves and therefore a blockage in the area of the former inlet is avoided by this. It is moreover advantageous that the paper webs can be conveyed up to the folding rollers, even as a train, where they are grasped by the latter and fed to the folding unit.
The paper webs guided by the belt guide devices have a stabilized running direction, so that a lateral excursion, and therefore interruptions of the sequence are prevented. The belt guide device of the present invention can also be employed for removing malfunctions with the running of the webs in the paper web feed device, or in the course of malfunctions with the running of the paper during the draw-in of the paper webs in the folding area.
The conveying means are aligned so they work in, or approximately in, the production direction.
In accordance with a variation of the present invention, lateral guide elements are provided, and extend on both sides of the lateral boundaries of the former surface as far as, or into the vicinity of the respective former roller.
A number of upper and lower conveying means, which are arranged above each other, are provided within the boundaries of the lateral guide elements.
Here, the upper and lower conveying means can be brought into and out of contact with each other and can be selectively driven.
In accordance with a first preferred embodiment of the present invention, a number of conveyor belts, which point in the direction of the surface of the lateral guide elements and which can be charged with suction air, are provided within the boundaries of the lateral guide elements.
In accordance with a second preferred embodiment, the conveying means consist of driven or of non-driven conveying rollers. In this embodiment, the lower and upper driven conveying rollers can act together, for example, or upper conveying rollers can work together with lower suction belts.
In accordance with a third preferred embodiment, the conveying means consist of driven driving or conveying chains.
In accordance with a fourth preferred embodiment, the conveying means can also consist of driven V-belts, flat belts or toothed belts.
A cover, which has slits for the lower conveying means, is suitably provided between the boundaries of the former.
Slits which expose the lower conveying means are also provided in the surfaces of the lateral guide elements.
It is advantageous if an outer paper guide plate is assigned to each of the lateral guide elements and is spaced apart from them. In this configuration, slits are provided in the outer paper guide plate for making access of the upper conveying means to the lower conveying means possible.
It might possibly be sufficient if a paper deflection device, which surrounds the lateral boundaries in the form of a shell, is provided along the lateral boundaries of the former and is spaced apart from them.
It is moreover practical that a paper guide device is provided which is also spaced apart from the former surface and covers it either completely or partially. In this case, the paper guide device arranged in the area of the former surface is provided with suitable slits for making access of the upper conveying means to the lower conveying means possible.
In accordance with a last preferred embodiment, it is also possible that the outer paper guide plate, which covers the lateral guide elements, and the portion of the outer paper guide device covering the former surface, are connected in the area of the lateral deflection elements, or adjoin each other without being connected.